Overview

CDP-choline (Citicoline) is a form of the B-vitamin choline. It is used by
the body to make cell membranes and also to make the neurotransmitter
acetylcholine.

CDP-choline began to be used in the 1960s as a treatment for
brain injuries, and interest in it has grown with the realization
that it offers a degree of protection against various kinds of
damage to the nervous system (including the retina and optic
nerve).

CDP-choline has been the focus of countless experiments using
cell culture and lab animals, and many thousands of human volunteers
and patients have participated in clinical studies of this
compound. There is now considerable evidence that CDP-choline has
neuro-protective and neuro-regenerative effects that can
ameliorate the following conditions:

glaucoma-related damage to the eye

amblyopia (poor vision in one eye; “lazy eye”)

Alzheimer’s Disease

Parkinson’s Disease

age-related learning and memory disorders

traumatic brain injury

stroke

drug addiction.

The brain-bioavailability of CDP-choline is low, because the
majority of the consumed dose is used outside of the brain. Fortunately
the substance is not terribly expensive and so the low
brain-bioavailability can be compensated for by using fairly large
doses — 1000 mg/day, for example. The lack of toxicity of the
supplement makes this possible without causing significant side
effects.

Read CDP-Choline (Citicoline) Monograph

CDP-choline is a form of the B-vitamin choline. It is an
intermediate in the synthesis of components of cell membranes and
of the neurotransmitter acetylcholine. It also is a precursor
of betaine, which is involved in gene regulation.

The biochemistry of CDP-choline has been studied since the
1950s and its clinical use began in the 1960s as a treatment for
brain injuries.1
Progress has been very slow, perhaps because the potential applications
of the substance were patented and were then subjected
to financial and legal game-playing by the patent owner and
licensees. Development was further plagued by clinical studies
that sometimes reached conflicting results. Even now there is
not yet a consensus on optimum dosages for various conditions.
Nevertheless, interest in this supplement remains high; and
there is general agreement that it offers a degree of protection
against various kinds of damage to the nervous system
(including the retina and optic nerve).

The neuroprotective effects of CDP-choline may derive from
its ability to increase the synthesis of phosphatidylcholines in
injured nervous tissue.2
Phosphatidylcholines are major components of cell membranes.

What we can’t tell you

In the U.S. and some other industrialized countries,
government agencies like the U.S. Food and Drug Administration have
adopted
censorship as a method for intensifying their control over the
supplement industry and its customers. Thus, FDA regulations
prohibit us from telling you that any of our products are
effective as medical treatments, even if they are, in fact,
effective.

Accordingly, we will limit our discussion of CDP-choline to a
brief summary of relevant research, and let you draw your own
conclusions about what medical conditions it may be effective
in treating.

CDP-choline has been the focus of countless experiments using
cell culture and lab animals, and many thousands of human volunteers
and patients have participated in clinical studies of this
compound.3
There is now considerable evidence that CDP-choline has neuroprotective
and neuro-regenerative effects that can ameliorate
the following conditions:3,4

CDP-choline as a treatment for visual problems

Two kinds of vision problems have been shown to be improved
by CDP-choline supplementation. Both are problems stemming from
damaged nerves.

Glaucoma results from damage to nerve cells which transmit
information from the retina into the brain. Treatment of glaucoma
patients with oral CDP-choline (1600 mg/day for 60 days)
resulted in “Improvement of retinal function (objectively evaluated
by pattern electroretinogram recordings) and of neural
conduction along visual pathways…”15

Amblyopia (a.k.a. “lazy eye”) is a visual disorder in which
one eye has poor vision despite having no significant defect in
the eye itself. It is thought to be caused by damage to the
brain's visual centers or to the optic nerve. CDP-choline has
been tested in children with amblyopia and found to improve
visual acuity, contrast sensitivity, and strength of visual responses.16
When combined with patching, it leads to more stable benefits than
those achieved with patching alone.14

CDP-choline for Alzheimer’s and Parkinson’s

When CDP-choline was administered to early-to-mid-stage
Parkinson’s patients it led to significant improvement in symptoms.
Advanced Parkinson’s patients appeared not to benefit from the
treatment.8,9

A number of clinical trials have demonstrated an ability of
CDP-choline to reverse the cognitive symptoms of Alzheimer’s Disease.
For example, in 1999 Spanish researchers reported that 1000
mg/day of CDP-choline “…Improves cognitive performance, cerebral
blood perfusion and the brain bioelectrical activity pattern in
AD patients.” The treatment was more effective in some types
of Alzheimer’s Disease than in others.6

CDP-choline’s action against Alzheimer’s symptoms may be due
in part to its ability to keep nerve cells alive under conditions
that normally would cause them to self-destruct. Some of the
damage done to the brain by Alzheimer’s Disease is thought to
be due to the triggering of cell suicide (“apoptosis”) by the
plaques of amyloid protein that are a hallmark of the disease.
A study in 1999 implanted amyloid protein in various parts of
rats’ brains. Those rats that were also treated with CDP-choline
suffered less neurodegeneration and performed better in
cognitive tests than rats that received no CDP-choline.17

Other age-related cognitive problems

Phosphatidylcholine — a major component of brain cell
membranes — is produced by the body in decreasing amounts as one ages.
It is thought that this decline lowers the efficiency of
signaling between nerve cells, and therefore impairs the processing
of information in the brain.18

Supplementation in “older subjects” with CDP-choline (500
mg/day for 6 weeks) has been shown to promote synapse formation
and efficiency, and to improve performance on the California
Verbal Learning Test.19,18,10

Traumatic brain injury

The toll taken by traumatic brain injury is enormous — every
year, approximately 1.4 million Americans sustain such an injury,
of which 50,000 die, another 235,000 are hospitalized, and
80,000–90,000 people suffer permanent disability.2

At long last, a major clinical trial has been organized to
find out whether CDP-choline’s benefits in stroke and dementia
can be translated into a treatment for traumatic brain injury.
The trial, called COBRIT, started in 2007 but is still recruiting
participants (as of April 2010); it is scheduled to be
completed in December 2010.20
We eagerly await the results, which we anticipate will catapult
CDP-choline into a first-line treatment for such injuries.

Stroke

CDP-choline as a treatment for stroke has received a
considerable amount of research attention. The evidence suggests that
if stroke patients are treated with 2000 mg of CDP-choline
within the first 24 hours after having the stroke, their probability
of complete recovery at 3 months will be increased by about 8%.5

Schizophrenia

In a recent collaboration between LifeLink and researchers at
Georgetown University and the U.S. Department of Veterans Affairs,
a new application for CDP-choline has been shown: treatment of
schizophrenia. Researchers previously had suspected that at
least some aspects of schizophrenia may be caused by a defect
in a molecular channel in nerve cell membranes — specifically,
a defect in the alpha7 nicotinic acetylcholine receptor located
in this channel. That suspicion has now been confirmed by
a 12-week-long clinical trial in which patients were given a
combination of CDP-choline (supplied by LifeLink) and the drug
galantamine; the trial showed that 5 out of 6 subjects
receiving this treatment experienced a “reduction in Clinical Global
Impressions severity scores and Positive and Negative Syndrome
Scale total scores.”22

Side effects

CDP-choline typically is without side effects. Rarely a few
users experience digestive intolerance, gastrointestinal discomfort
or restlessness.3

Bioavailability

When taken orally CDP-choline is converted in the intestine
into cytidine and choline, both of which are efficiently absorbed
into the bloodstream.21
These components are then transported throughout the body where they
are utilized in various biosynthetic pathways.4
A small fraction of the cytidine and choline pass through the
blood-brain barrier and are converted in the brain back into
CDP-choline.4

The brain-bioavailability of CDP-choline is therefore low,
since the majority of the consumed dose is used (or wasted) outside
of the brain. Fortunately the substance is not prohibitively
expensive and the low brain-bioavailability can be compensated
for by using fairly large doses — 1000 mg/day, for example. The
lack of toxicity of the supplement makes this possible without
causing significant side effects.

Conclusion

Are CDP-choline supplements useful for the conditions and
purposes mentioned above? We aren’t allowed to tell you, so you
should take a look at some of the references cited here, and
then decide for yourself.